3 Gorges Dam

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A Few Facts on The Three Gorges Project

• Project expected to take 17 years; although it has been completed it still is being worked on.
• An estimated 250,000 workers are involved in the project.
• The Three Gorges Reservoir will inundate 632 square kilometers (395 square miles) of land.
• An estimated 1.2 million people will be resettled by the dam.
• The project's 26 hydropower turbines are expected to produce 18.2 million kilowatts, up to one-ninth of China's output.
• The amount of concrete totals 26.43 million cubic meters, twice that of the Itapúa project in Brazil, currently the world's largest hydroelectric dam.
Source: Chinese government


A Brief History

The 3 Gorges Dam was first suggested by Sun Yat-sen, founder of the Republic of China. He suggested the Dam on the Yangzte River in central China’s Hubei Province to protect the river communities from deadly floods. The construction began on the dam in 1993 and has taken until 2009 to complete.

Environmental and Geological Problems

There are many concerns with the Three Gorges Dam. These concerns consist of environmental and geological problems.Some of the problems that the Three Gorges Dam faces are: flooding, landslides, and erosion problems occurring around the dam itself and on the Yangtze River.

The dam is supposed to be an engineering feat, and be the World’s largest hydropower project anyone has ever seen. It should be one that will surpass other large engineering projects. The dam is supposed to help with flooding and also be a way of a clean energy and power source for China, so that they don’t have to rely on coal as their large power source. Many people feel that the dam will not be as successful as it was sought out to be. They feel that it will cause further problems that will take years to clean up. The flooding of the Yangtze River has caused factories, waste dumps, and mines to be under water. This leads to additional environmental problems including pollution. Officials from the Xinhua news agency in China are saying that the size of the reservoir, which is located behind the Three Gorges Dam, has started to erode the Yangtze’s River banks due to the fact that there are frequent changes in water levels. This is causing landslides to occur all over parts of the Yangtze River and the Three Gorges Dam. Studies conducted by geologists have shown that the water seeping out of the reservoir and the huge pressure changes are weakening the banks and causing these landslides.

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Scientists, geologists, and government officials have been studying for years that Three Gorges Dam contains reservoir-induced seismicity, known as RIS. Reservoir induced seismicity is in the dam and can cause earthquakes. If the reservoir is deeper than 100 meters (328 ft), then RIS can occur. The reservoir is over 500 ft deep and up to 370 mi long, so the dam has a good chance of causing an earthquake. Scientists have said, “The best explanation of how dams can cause earthquakes is related to the extra water pressure that is created in the small cracks and fissures in the groundwater and near a reservoir. When the pressure in the rocks increases, it acts to lubricate faults which are already under lots of tectonic strains, but are prevented from slipping by the friction of the rock surfaces”. This then creates earthquakes which cause massive problems for the rest of the country.

Energy Production

There have been many pros and cons to the construction of the 3 Gorges Dam in China. China is ranked number two in consumption of energy worldwide. They mainly use coal, so once the dam is fully running this will produce the main source of energy of the country as hydro power. This will greatly reduce the amount of carbon dioxide and sulfur dioxide into the atmosphere, which ultimately leads to global warming. It is expected to also reduce millions of tons of dust and a significant amount of Mercury. It is expected to reduce the amount of coal China uses by 40 million tons. It has a very large growing population so it may appear in the best interest of the government to control nature to help out its population. However the question remains, does controlling nature cause more harm than good? There have been potential dangerous side effects from attempting to control a large problem. We will be looking at the reasons behind the construction of the dam and why it was necessary, the environmental and geological concerns, the outcomes of the project and our thoughts behind the dam.

Generators

The Three Gorges Dam has 34 generators, 32 which are main generators with a capacity of 700 MW (Million Watts), and 2 which will are plant power generators with a capacity of 50 MW. Among the 32 generators 14 will are on the north side of the dam, 12 on the south side and the other 6 in the underground power plant which is located in the mountain on the south side of the dam. The annual electricity generated is estimated to be over 100 TW (Trillion Watts).

Since September 16, 2009 the Three Gorges Dam generated 348.4 TW of electricity. This is more than one third the amount of the 1000 TW needed to recover the costs they have invested. Depending on the month of the year and the water levels of the Yangtze River, determines the amount of electricity generated in that month. In July of 2008, the Three Gorges Dam generated 10.3 TW of electricity which is the first time it has ever exceeded 10.0 TW. In August of 2009, the Yangtze River experienced high water levels due to a flood. The generators reached their maximum output of 18,300 MW for a short period of time. During dry months like November through May, the dam experiences minimum output due to the low water levels and flow rate.


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Above is a diagram that compares the Yangze River flow to the Three Gorges Dam intake capacity

Flood Control

Originally the dam was going to be constructed to help with flooding in the Yangtze River area of China. There had been very high flooding in the area of the Yangtze River; it is the third largest river in the world. Over the course of 2000 years there have been over 200 catastrophic floods. The river receives additional water from 4 out of 5 of China's lakes, which causes additional waters to cause flooding. Over the past 180 years scientists have been trying to come up with a way to control the flooding. The idea for a dam began in 1918. The dam plans continued to grow at a rapid pace, especially after the 1954 flood that caused over 30,000 people to die. The Yangtze River is very important to China’s economic growth. Millions of people live in cities like Wuhan and Nanjing that are located directly downstream. Shanghai is also located adjacent to the river. Along the river is some of China’s best farmland and industrial areas. The reservoirs flood storage capacity is 22 km cubed. This will reduce the chances of flooding from one every 10 years to one every 100 years. However, in the act of “super flood” the dam would only minimize effects.

The 3 Gorges Dam did do an excellent job of controlling the initial problem of flooding, but has created some problems that are of great concern. The first concern is the direct correlation to the increased reduction in the Baiji population. Commonly known as the Chinese River Dolphin this animal is in great danger due to the dam building. The dam decreases the natural flushing abilities of the river itself therefore the pollutants in the river have grown to an uninhabitable level for many species, specifically the Baiji. As of the last check done in 2006 there was not one single Baiji found in the river. That means that the dam has had a direct correlation to forcing the Baiji into being a functionally extinct animal in this world.


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The Baiji Dolphin, It's only natural habitat was the Yangtze River.
Another concern is the artifacts that are being excavated around the river before the dam. Many of these ancient and irreplaceable artifacts are now being flooded under by the rising river beds in the areas about the dam. Although some excavation sites can be moved, we will never be able to replace what could and would have been found in the original excavation locations. Some sights are even artifacts themselves and cannot be moved as they are part of the landscape itself.

Navigation

Navigation for more than 10,000 barges will be accessible along the upper Yangtze River because of the huge reservoir created by the dam. In the past, because of low water levels more than 3,500 barges have been limited to this passage. This will increase the trade and reduce freight costs to China’s most populous municipality Chongqing. This is expected to increase the river shipping from 10 million to 100 million annually. The Three Gorges Dam will also be equipped with ship lifts that acts like elevators for vessels. It is designed to lift ships as big as 3,000 tons and expected to take 30-40 minutes to ascend or descend compared to the three to four hours going through the main locks.

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There are also to project concerns the dam itself. One concern is that the dam was built on a seismic fault. Another concern is the dam sediment projections were never agreed upon. That uncertainty could lead to unseen bi-products of the dam building. The building on the fault also increases the concern of natural disaster damage that could lead to more flooding than ever before.

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Impact on civilians and those involved

The three gorges dam has had a major effect on people. The most notable is the relocation of residents around the dam area. The Yangtze River dammed up the water levels rise and create a large reservoir which has overtaken many small villages on the banks and hills of the Yangtze River. An estimated 1.24 million so far and they aren’t done yet. The government would like to see another 4 million people from the area move to the Chongqing metro area in the next decade. This will cause some overcrowding in the surrounding urban areas. The flooding of the reservoir has overtaken archeological sites numbering around 1300. There are positives; the dam produces roughly 80 TWh of energy a year, going to nine provinces and two cities, one being the large city of Shanghai. In all, the dam will affect nineteen countries putting it to around fourteen million people. Apart from the submergence of cities and hundreds of villages it will put 44,000 hectares of fertile farmland. The farmers who tended that land are gone as well. It is a blow to the food market in China. There are two other groups affected by the dam, those who have invested their money in it and those who worked or still work on the dam. The dam cost seventy five billion dollars in US currency to give the cost a home view. It employed thousands of workers to construct the dam over its 18 year period, and will employ a shockingly low 370 employees to run at full power, far short of the 5,000 employee estimate.

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From an environmental perspective it makes a lot of sense to construct a dam. It is important to do something to prevent the loss of human life and property from flooding. The Yangtze river has been a huge problem for China with flooding over the years and it it was a brilliant solution to the problem. Another environmental pro is that it will help with using our natural resources of coal for energy. In a nation as large as China this is a huge benefit to the environment because it will cause less pollution. The long run benefit to the depletion of natural resources will outweigh some of the risks associated. However, the dam is causing significant damage to the environment around it. At this point the dam may end up costing more money and just as much use of resources to clean up the problems it is causing. The earthquakes and landslides may eventually cause more harm than the flooding would have done. The dam is a classical example of man trying to control nature for its own purposes. It is hard to say if it would have been best to leave the river alone or put up the dam because both options have left destruction in its paths.

http://darwin.bio.uci.edu/~sustain/state/kmin.html http://www.internationalrivers.org/en/china/three-gorges-damm http://en.wikipedia.org/wiki/Three_Gorges_Dam http://www1.american.edu/ted/THREEDAM.htm http://thewe.cc/weplanet/news/asia/china/three_gorges_dam.html